We now compute the cap-height from the rasterized glyph data.
Moved the scaling action of use_cap_height_to_scale_fallback_fonts from
glyphcache into the font resolver: when enabled, and we have data
about the baseline font and the font being resolved, then the resolving
font will be scaled such that the cap-height of both fonts has the same
pixel size.
The effect of this is that `I` glyphs from both fonts should appear to
have the same height.
Added a row of `I`'s in differing styles at the bottom of styles.txt
to make this easier to visualize.
refs: #1189
With this configuration:
```lua
local wezterm = require 'wezterm'
return {
font_dirs = {"/Users/wez/Downloads/Inconsolata"},
font = wezterm.font("Inconsolata"),
font_locator = "ConfigDirsOnly"
}
```
wezterm is now able to see the 74 variations that are available
in the single inconsolata ttf.
Running `WEZTERM_LOG=wezterm_font=trace wezterm` will log the
variations.
refs: https://github.com/wez/wezterm/issues/655
By default, freetype doesn't include error strings and FT_Error_String
will always return NULL. Turn on the compile time option that makes
this function useful!
This commit more cleanly separates the load from the render flags,
and fixes up the render call; at some point this got messed up such
that we'd never end up with freetype returning subpixel format data
(LCD) and instead we'd only ever get grayscale data.
With that fixed, it's apparent that the colorization of the glyph
data was wonky in the shader so this commit also cleans this up.
refs: #320
refs: #121
Forgetting to update the submodules is a commonly reported build
issue with an obscure error message:
```
CMake Error: The source directory "/home/USER/wezterm/target/debug/build/freetype-430fe24cb64c561c/out/zlib-src/zlib" does not appear to contain CMakeLists.txt.
```
this teaches the build.rs machinery to run the submodule update
if it looks like it is needed.
This is primarily for macos where the default freetype
installation is unable to render color emoji, but should also
help make things more consistent across the various platforms.
It's a little bit awkward on linux because the font-loader crate
pulls in the now-conflicting servo-font* crates. I've disabled
font-loader on linux systems; it's just calling fontconfig under
the covers anyway.
